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Phylum Chordata > Subphylum Vertebrata > fishes > Family Ostraciidae
Shortnose boxfish
Rhynchostracion nasus
Family Ostraciidae
updated Sep 2020

Where seen? This strange boxy fish is sometimes seen on some of our shores. It is also called the Small nosed boxfish. It was previously called Ostracion nasus.

Features: To 30cm, those seen about 10cm long. Body cubical boxy, which is enclosed in a protective hard shell (carapace) made up of bony plates with gaps for the various tiny fins, the tail and the mouth. No horns. A small bump on the 'nose' above the upper lip and a ridge along the middle of the back. Body pattern of hexagons with brown spots.

Cyrene Reef, Jun 09

Cyrene Reef, Jun 09
Toxic box: It is said to be toxic. It is probably one of the species that secretes a powerful toxin on the skin (called ostracitoxin). This toxin is poisonous to other fishes and can even kill the boxfish itself if it is confined in an aquarium. Thus they are not recommended for aquariums.

Shortnose boxfishes on Singapore shores
On wildsingapore flickr

Other sightings on Singapore shores

Beting Bronok, Jun 16
Photo shared by Jianlin Liu on facebook.

Beting Bronok, Jul 19
Photo shared by Jianlin Liu on facebook.

Pulau Sekudu, Jun 14

Pulau Sekudu, Jun 14
Photo shared by Marcus Ng on facebook.

Changi Fairy Point, Jul 22
Photo shared by Kelvin Yong on facebook.



  • Tan Heok Hui . 30 November 2016. Sexual dimorphism in shortnose boxfish sold for food. Singapore Biodiversity Records 2016: 169-170.
  • Allen, Gerry, 2000. Marine Fishes of South-East Asia: A Field Guide for Anglers and Divers. Periplus Editions. 292 pp.
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